Results 1 to 10 of about 1,225 (187)
NuSTAR Detection of an Absorption Feature in ESP 39607: Evidence for an Ultrafast Inflow?
The Astrophysical JournalWe report the serendipitous discovery of an absorption feature at 4.8 keV in the NuSTAR spectra of ESP 39607, a Seyfert 2 galaxy at z = 0.201, observed in 2023 May and 2024 August. The feature is detected in both observations with individual significance
Alessandro Peca +6 more
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The Astrophysical Journal LettersThe high-energy-peaked BL Lacertae objects (HBLs) are the main targets of the Imaging X-ray Polarimetry Explorer (IXPE) for investigating the mechanisms of radiation and particle acceleration in jets. In this Letter, we report the first IXPE observations
Xin-Ke Hu +7 more
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A Long-term Study of Mrk 50: Appearance and Disappearance of Soft Excess
The Astrophysical JournalWe present an extensive temporal and spectral study of the Seyfert 1 AGN Mrk 50 using 15 yr (2007–2022) of multiwavelength observations from XMM-Newton, Swift, and NuSTAR for the first time.
Narendranath Layek +3 more
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Discovery of Changing-look Behavior in AGN NGC 3822: A Long-term Multiwavelength Study
The Astrophysical JournalWe present a comprehensive long-term multiwavelength study of the active galactic nucleus NGC 3822, based on 17 yr (2008–2025) of X-ray, ultraviolet (UV), and optical observations. The data set includes observations from Swift , XMM - Newton, and NuSTAR,
Narendranath Layek +9 more
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A Systematic Search for Active Galactic Nuclei Obscuration Variability in the Chandra Archive
The Astrophysical JournalThe nature of the obscuring material in active galactic nuclei (AGN) can be studied by measuring changes in the line-of-sight column density, N _H,LOS , over time. This can be accomplished by monitoring AGN over long periods of time and at all timescales.
Isaiah S. Cox +7 more
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On the Extended Soft X-Ray and Fe Kα Emission in NGC 1068
The Astrophysical JournalThe soft X-ray excess and Fe K α emission lines are widely observed in Seyfert galaxies, with their origin still in debate. We present a detailed spatially resolved image and spectral analysis of the Seyfert 2 galaxy NGC 1068 using high-resolution ...
Songbo Gao, Hongxing Yin, Shaoming Hu
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The Astrophysical JournalWe present an enhanced version of the publicly available Stripe 82X catalog (S82-XL), featuring a comprehensive set of 22,737 unique X-ray point sources identified with a significance ≳4 σ .
Alessandro Peca +11 more
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First X-Ray Polarimetric View of a Low-luminosity Active Galactic Nucleus: The Case of NGC 2110
The Astrophysical JournalLow-luminosity active galactic nuclei (LLAGN) provide a unique view of Comptonization and nonthermal emission from accreting black holes in the low accretion rate regime.
Sudip Chakraborty +23 more
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Systematic Monitoring of Extreme X-Ray Variability from Weak-line Quasars
The Astrophysical JournalWe present the results of a multicycle Chandra program to systematically monitor the X-ray variability of 10 weak-line quasars (WLQs) that previously had limited multiepoch X-ray observations.
Madison Reich +7 more
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The Astrophysical Journal LettersWe present the first high-resolution X-ray spectrum of NGC 7213 obtained with XRISM/Resolve, supported by simultaneous XMM-Newton, NuSTAR, and SOAR optical data.
E. Kammoun +51 more
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